In recent years a number of new mulching materials have become available. Many of these mulches are recycled products, including yard waste materials diverted from landfills. The charts below provide information about these products, as well as some of the more traditional mulches.
Mulches can be divided into two basic categories–inorganic and organic. Organic materials are composed of plant or animal residues, and break down over time. Inorganic mulches are natural or man-made materials that do not decompose, or decompose very slowly.
When choosing mulch, basic considerations include cost, appearance, and longevity. Consult local suppliers for cost comparisons. Appearance is largely a matter of personal taste. Some people use more attractive and expensive mulches in areas of high visibility, and less expensive mulches in lower visibility sites. Longevity refers to the length of time required for a mulch to break down. One of the benefits of mulches is their ability to improve soils by adding organic matter as they decompose. Mulches that break down slowly improve the soil slowly, but do not need to be reapplied as frequently. In contrast, mulches that break down more quickly provide better soil benefits, but need to be applied more regularly. For sites with poor soils, selecting a mulch with a shorter longevity may be the best option.
For additional information on the benefits of mulching, and techniques for proper mulching, refer to HYG-1083-96, Mulching Landscape Plants.
|Stone, gravel, lava rock, pebbles||Very long||fire resistant resist blowing or washing on slopes typically used with plastic mulches or landscape fabric underneath these materials white and light colored rocks radiate sunlight, creating too much light for some plants clean-up of leaves, needles, and twigs can be difficult do not break down, so provide no benefit to the soil can roll onto walkways, creating a nuisance limestone products increase soil pH, often to detrimental levels|
|Ground or shredded tires||Very long||ideal for use in playgrounds, due to cushioning capabilities not conducive for landscape use|
|Organic Mulches–Traditional Bark Mulches|
|Pine bark and nuggets||Long||slow to decompose, but an excellent mulch material excellent weed control nuggets can roll onto walkways, creating a nuisance|
|Cypress||Medium-long||excellent weed control may cause nitrogen deficienc|
|Shredded hardwood||Medium-long||excellent weed control may cause slight nitrogen deficiency|
|Organic Mulches–Recycled Products|
|Composted yard wastes|
(prepared from yard wastes such as brush, leaves, grass clippings, etc.)
|Medium||good for soil improvement finely ground materials are ideally suited for soil preparation, while coarser products are better for mulching particularly useful on new home sites with poor quality topsoil application of a thin layer of pine bark on top of compost improves longevity and weed control|
|Composted leaves||Short||more suitable as a soil amendment than a mulch especially useful in preparation of seed and planting beds|
|Ground and dyed wood pallets||Medium||material is dyed to resemble traditional bark mulchesand other recycled wood products good for paths, picnic areas, etc. causes nitrogen deficiency, particularly with annuals and perennials|
|Wood chips||Medium||ideal for use on established landscape plantings and trees causes nitrogen deficiency if not properly composted first|
Organic Mulches–Mulch Blends
Some mulches offered for sale are a blend of two or more products. Typically blends are mixtures of finely ground compost and coarser products such as tree barks and/or dyed wood mulches. These blends can make ideal mulches.